Comparing Ls1, Ls3, and Ls7 Swaps for Rx-7: Power, Cost, and Complexity

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The RX-7 has long been a favorite among car enthusiasts, particularly for its lightweight design and rotary engine. However, many have turned to LS swaps for increased power and reliability. This article compares the LS1, LS3, and LS7 engine swaps for the RX-7, focusing on power, cost, and complexity.

Overview of LS Engine Swaps

LS engine swaps have gained popularity due to their performance capabilities and availability. Below are the key factors to consider when evaluating LS1, LS3, and LS7 swaps for the RX-7.

Power Comparison

One of the primary reasons for an LS swap is the significant increase in power. Here’s a breakdown of the power output for each engine:

  • LS1: Approximately 305-350 horsepower depending on the year and modifications.
  • LS3: Offers around 430 horsepower, providing a substantial boost over the LS1.
  • LS7: The most powerful of the three, producing about 505 horsepower, ideal for high-performance builds.

Cost Analysis

Cost is a critical factor when considering an engine swap. Below is an overview of the estimated costs for each engine swap:

  • LS1 Swap: Generally the most budget-friendly option, with complete swaps ranging from $3,000 to $6,000.
  • LS3 Swap: The cost increases significantly, typically ranging from $7,000 to $10,000 for a complete swap.
  • LS7 Swap: The most expensive option, with costs often exceeding $15,000 due to the engine’s price and additional modifications needed.

Complexity of the Swap

The complexity of the swap can greatly affect the overall experience. Here’s a look at how each engine swap ranks in terms of complexity:

  • LS1 Swap: Generally considered the easiest swap due to its compatibility with the RX-7 and the availability of kits and resources.
  • LS3 Swap: More complex than the LS1, requiring additional modifications for fitment and wiring.
  • LS7 Swap: The most complex, often requiring custom fabrication and advanced tuning to ensure optimal performance.

Conclusion

When choosing between an LS1, LS3, or LS7 swap for the RX-7, it’s essential to weigh the power, cost, and complexity of each option. The LS1 offers a budget-friendly and straightforward solution, while the LS3 provides a balance of power and cost. The LS7, while the most powerful, also presents the highest complexity and expense. Ultimately, the choice depends on your performance goals and budget.